Structural and vibrational properties of SnxGe1-x: Modeling and experiments

The effects of composition and macroscopic strain on the structural properties and lattice vibrations of SnxGe1-x solid solutions (SSs) are investigated numerically, employing Tersoff empirical inter-atomic potentials, and experimentally. The calculations provide statistical distributions of bond lengths, pair correlation function and vibrational Raman spectra of the SSs. Using this approach, we are able to evaluate the tin-content-dependent shifts due to the local environment (i.e changes in the atomic mass and bond stiffness) and strain effects in the calculated Raman spectra and compare them to experimental data. The relative importance of the composition dependent effects of the local environment and strain for epitaxial layers of GeSn solid solutions is analysed.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Plurianual Strategic Funding UID/FIS/04650/2013. FO acknowledges the FCT PhD Grant and thanks the Institut für Halbleitertechnik, Universität Stuttgart for hospitality.info:eu-repo/semantics/publishedVersio

Problematika određivanja količine istaloženih azotnih jedinjenja na slatinska staništa nacionalne ekološke mreže

The exceedance in the critical load of nitrogen compounds is used by the European Environment Agency as an indicator of the biodiversity loss risk. This paper provides a general overview of continental saline habitats vulnerability (Slatine - in Serbian) located in central Banat within the National Ecological Network, caused by the deposition of nitrogen compounds. These compounds originate from manure of selected category of animals raised in settlements located in the vicinity of protected areas. The data on short-range deposition of nitrogen compounds within two zones were used for determining the areas of impact: the zone of probable impact (0-500 m) and the zone of potential impact (500-2000 m). According to the calculation results, the most vulnerable locations which, for the most part, belong to 'Rusanda' protected area, are the pastures directly surrounding village Kumane, pastures bordering Rusanda salty lake, including the lake itself.Prekoračenja kritičnih opterećenja azotnim jedinjenjima se koriste kao indikatori rizika gubitka biodiverziteta od strane Evropske agencije za životnu sredinu. U radu je dat okvirni prikaz ugroženosti slatinskih staništa nacionalne ekološke mreže koja je uzrokovana taloženjem azotnih jedinjenja iz stajnjaka izabranih životinja, poreklom iz naselja koja se nalaze u okruženju zaštićenih područja srednjeg dela Banata. Za određivanje oblasti uticaja korišćeni su podaci o kratkom dometu taloženja azotnih jedinjenja, unutar dva pojasa: pojas verovatnog uticaja (od granice zaštićenog područja do 500 m) i pojas mogućeg uticaja (500-2000 m). Na osnovu rezultata proračuna, kao posebno ugroženi lokaliteti izdvajaju se pašnjačke površine u neposrednom okruženju naselja Kumane koje najvećim delom pripadaju zaštićenom području 'Rusanda', pašnjaci uz Rusandu, kao i samo jezero

Synapsin Regulates Activity-Dependent Outgrowth of Synaptic Boutons at the Drosophila Neuromuscular Junction

Patterned depolarization of Drosophila motor neurons can rapidly induce the outgrowth of new synaptic boutons at the larval neuromuscular junction (NMJ), providing a model system to investigate mechanisms underlying acute structural plasticity. Correlative light and electron microscopy analysis revealed that new boutons typically form near the edge of postsynaptic reticulums of presynaptic boutons. Unlike mature boutons, new varicosities have synaptic vesicles which are distributed uniformly throughout the bouton and undeveloped postsynaptic specializations. To characterize the presynaptic mechanisms mediating new synaptic growth induced by patterned activity, we investigated the formation of new boutons in NMJs lacking synapsin [Syn(−)], a synaptic protein important for vesicle clustering, neurodevelopment, and plasticity. We found that budding of new boutons at Syn(−) NMJs was significantly diminished, and that new boutons in Syn(−) preparations were smaller and had reduced synaptic vesicle density. Since synapsin is a target of protein kinase A (PKA), we assayed whether activity-dependent synaptic growth is regulated via a cAMP/PKA/synapsin pathway. We pretreated preparations with forskolin to raise cAMP levels and found this manipulation significantly enhanced activity-dependent synaptic growth in control but not Syn(−) preparations. To examine the trafficking of synapsin during synaptic growth, we generated transgenic animals expressing fluorescently tagged synapsin. Fluorescence recovery after photobleaching analysis revealed that patterned depolarization promoted synapsin movement between boutons. During new synaptic bouton formation, synapsin redistributed upon stimulation toward the sites of varicosity outgrowth. These findings support a model whereby synapsin accumulates at sites of synaptic growth and facilitates budding of new boutons via a cAMP/PKA-dependent pathway.National Institutes of Health (U.S.) (Grant R01 MH099557

Efekat biouglja na morfološka svojstva kukuruza i soje

This paper analyses the effects of the biochar application morphological traits in maize and soybean under semi-controlled conditions. During the study, the increasing doses of biochar (0%, 0.5%, 1, 3, and 5%) were incorporated in three soil types: Alluvium, Humogley and Chernozem to determine plant height and shoot weight. The experiment was set up as fully randomized design with three repetitions. The plants were grown in pots of 5 l with controlled watering and N fertilization. The research results have shown that there are differences in terms of biochar effects on soils. The greatest effect on plant height and shoot weight was obtained when the biochar was applied to Humogley soil and lower effects were found on the Alluvium soil. The increase in aboveground mass of maize and soybeans was significantly conditioned by adding different doses of biochar. Based on these results, it can be concluded that adding biochar can significantly affect the growth of plants. This is a consequence of the changes it causes in soil, which requires further tests to complement the current findings.U radu je ispitivan uticaj primene biouglja na morfološka svojstva kukuruza i soje u polukontrolisanim uslovima. Primenjene su rastuće doze biouglja na tri tipa zemljišta: aluvijum, černozem i humoglej i praćena je visina biljaka i masa nadzemnog dela. Ogled je postavljen po randomiziranom rasporedu sa tri ponavljanja u sudove zapremine 5 litara, a setva je izvršena u mesecu maju. Rezultati istraživanja su pokazali da postoje razlike u pogledu ispitivanih zemljišta i primenjenih doza biouglja. Najbolji efekat je dobijen kada je biougalj primenjen na zemljište humoglej a najmanji uticaj primene biouglja je utvrđen na aluvijalnom zemljištu. Porast nadzemne mase kukuruza i soje bio je u značajnoj meri uslovljen dodavanjem različitih doza biouglja. Na osnovu dobijenih rezultata može se zaključiti da dodavanje biouglja može značajno uticati na porast biljaka koji je posledica promene koje on izaziva u svojstvima zemljišta, ali da je neophodno nastaviti dalja ispitivanja kako bi se upotpunila dosadašnja saznanja. Utvrđeno je da su ispitivana svojstva kod soje ispoljila veću reakciju na primenu biouglja u odnosu na kukuruz

Description of Fischer Clusters Formation in Supercooled Liquids Within Framework of Continual Theory of Defects

Liquid is represented as complicated system of disclinations according to defect description of liquids and glasses. The expressions for the linear disclination field of an arbitrary form and energy of inter-disclination interaction are derived in the framework of gauge theory of defects. It allows us to describe liquid as a disordered system of topological moments and reduce this model to the Edwards--Anderson model with large-range interaction. Within the framework of this approach vitrifying is represented as a "hierarchical" phase transition. The suggested model allows us to explain the process of the Fischer clusters formation and the slow dynamics in supercooled liquids close to the liquid--glass transition point

Effect of melt composition on the reaction of uranium dioxide with hydrogen chloride in molten alkali chlorides

The reaction of uranium dioxide with excess hydrogen chloride in alkali chloride melts (LiCl, 3LiCl-2KCl, NaCl-KCl and NaCl-2CsCl) has been studied between 450 and 750°C, and the reaction products were characterized by electronic absorption and X-ray absorption spectroscopy. Uranium(V), [UO 2Cl4]3-, and uranium(IV), [UCl 6]2-, species were formed. They depended upon the temperature and the radius of the alkali cations present. Uranium(V) ions predominated in melts with small cations (LiCl and 3LiCl-2KCl). © 2007 Verlag der Zeitschrift für Naturforschung

Critical behavior of the fluctuation heat capacity near the glass transition of metallic glasses

The high-frequency shear modulus of five Zr-, Pd-, Cu-based conventional and two high-entropy bulk metallic glasses was measured in a wide temperature range up to the beginning of crystallization. Using these data and general thermodynamic relations, the "fluctuation" heat capacity $\Delta C_f$ determined by local structural fluctuations in the defect regions is introduced and calculated. It is found that $\Delta C_f$ temperature dependence for all metallic glasses has a large peak located slightly below or above the glass transition temperature but clearly lower than the crystallization onset temperature. The form of this peak resembles the characteristic $\lambda$-peak typical for order-disorder phase transitions. It is suggested that this $\Delta C_f$-peak reflects certain underlying critical phenomenon. The critical temperature $T_0$ (peak temperature) and corresponding critical index $\alpha$ are determined. Averaged over all seven metallic glasses under investigation in the initial and relaxed states, the critical index $\alpha=0.26$. The results obtained indicate that the fluctuations of thermal energy near the glass transition bear the marks of a continuous phase transition. However, the derived critical index is between those corresponding to a second-order phase transition ($\alpha\approx 0.1$) and a critical transition characterized by a tricritical point ($\alpha \approx 0.5$).Comment: 18 pages, 4 figure

The brief COPE-A inventory in Russian for adolescents: Validation and evaluation of psychometric properties

In this paper, the results of a psychometric analysis of a Brief Russian-language version of the COPE-A inventory for adolescents are presented. The inventory was designed for identifying coping strategies used in stressful situations and is comprised of 31 items. The study involved 3530 adolescents aged 13 to 17 years old. Using exploratory factor analysis and confirmatory factor analysis, it was shown that the data correspond to the expected six-factor configuration, but the distribution of items by factors differs from the theoretical structure. To improve the factor structure, two questions were excluded; the final version included 29 items. The resulting inventory's scales turned out to be highly reliable (Cronbach's alpha values range from 0.72 to 0.89). Additionally, the construct validity of the method was assessed. In conclusion, the adapted version of the Brief COPE-A is suitable for use in the adolescent population. © 2023 The AuthorsRussian Science Foundation, RSF: 17-78-30028This study was supported by the Russian Science Foundation [ 17-78-30028 ]

Direct J/psi and psi' hadroproduction via fragmentation in the collinear parton model and k_T-factorization approach

The p_T-spectra for direct J/psi and psi' in hadroproduction at Tevatron energy have been calculated based on NRQCD formalism and fragmentation approximation in the collinear parton model and k_T-factorization approach. We have described the CDF data and obtained a good agreement between the predictions obtained in the parton model and k_T-factorization approach. We performed the calculations using the relevant leading order in alpha_s hard amplitudes and the equal values of the color-octet long-distance matrix elements for the both models.Comment: 10 pages, Latex, 4 eps figures, epsfig.sty, graphics.st